U.S. Pat. No. 7,526,060 discloses that the reconstruction of images of an object of interest may introduce artifacts along lines of high gradients of absorption values. These artifacts may be removed by a statistical weighing during reconstruction of the image.
U.S. patent application Ser. No. 11/577,041 discloses a method for reducing artifacts in an original computed tomography (CT) image of a subject produced from original sinogram data. In the method an artifact creating object is re-projected in the original sinogram data to produce modified sinogram data in which missing projection data is absent. Replacement data for the missing projection data is interpolated and replaces the missing projection data in the original sinogram data. A final CT image is reconstructed using the final sinogram data to obtain an artifact-reduced CT image.
International Patent Application Publication No. WO 2012/056379 discloses a method that includes displaying at least one of projection data or reconstructed image data having visually observable artifacts. One or more sample images having artifacts similar to the visually observable artifacts are identified. Information about the identified one or more of the sample images is displayed.
International Patent Application Publication No. WO 2008/065394 discloses a method and apparatus for reducing artifacts caused by a metal implant, thorax/pelvic streaking, and lower dose streaking in reconstruction images. An initial reconstruction of the object using an iterative process is performed and an ideal correspondence of the implant is generated. A region affected by the implant is located and inconsistencies caused by the implant inside a scanned object are detected and analyzed. The initial reconstruction the real correspondence of the implant is approximated and the initial reconstruction is updated. The approximated correspondence of the implant is isolated and the implant-free reconstruction in the location of the implant synthesized.
International Patent Application Publication No. WO 2005/076221 discloses a reconstruction processor that reconstructs acquired projection data into an uncorrected reconstructed image. A classifying algorithm classifies pixels of the uncorrected reconstruction image at least into metal, bone, tissue, and air pixel classes. A pixel replacement algorithm replaces metal class pixels of the uncorrected reconstruction image with pixel values of the bone density class to generate a metal free image. A morphological algorithm applies prior knowledge of the subject's anatomy to the metal free image to correct the shapes of the class regions to generate a model tomogram image. A forward projector forward projects the model tomogram image to generate model projection data. A corrupted rays identifying algorithm identifies the rays in the original projection data which lie through the regions containing metal objects. A corrupted rays replacement algorithm replaces the corrupted regions with corresponding regions of the model projection data to generate corrected projection data. The reconstruction processor reconstructs the corrected projection data into a corrected reconstructed 3D image.
International Patent Application Publication No. WO 2005/076222 discloses the correction of artifacts caused by high attenuating objects. Artifact correction is provided in reconstructed images by correcting beam-hardening artifacts caused by high attenuating objects on the basis of a physical correction method, which uses the data in the shadow of the high attenuating objects without disregarding any physical information. The noise of line integral through high attenuating objects is reduced by using adaptively filtered projections.
International Patent Application Publication No WO 2003/009215 discloses a system and method for reducing streak artifacts and eliminating inhomogeneity in CT imaging by correcting elimination and using adaptive three-dimensional filtering. A direction of streak artifacts and a degree of inhomogeneous densities are estimated by gray scale morphology dilation.
International Patent Application Publication No. WO 2002/086822 discloses a method for artifact reduction in CT imagines that includes reconstructing a first data imaging using an inexact reconstruction algorithm. The first data image is segmented to provide a second image with high attenuation objects separated from low attenuation objects. The second image is re-projected to form a second set of data and a third image is reconstructed from the second data set using an inexact reconstruction algorithm. At least those portions of the third image outside of the high attenuation object are subtracted from the first image.